Stage 1 mesothelioma is the earliest stage of the disease. The cancer is still localized to one part of the body, like the lining of the lungs, and hasn’t spread to any nearby organs or lymph nodes. Patients at this stage rarely experience symptoms, which adds to the difficulty of diagnosing mesothelioma early.

For patients who are able to be diagnosed at this stage, curative treatment options are available. Stage 1 mesothelioma patients have the best prognosis, with an average survival of 21 – 40 months.

Stage 1 Mesothelioma by Type

Because the cancer is localized and tumors are generally smaller at this point, all types of mesothelioma diagnosed at stage 1 have the most curative treatment options available, like surgical resection. With no metastasis and more treatment options, patients have a longer life expectancy.

Stage 1 Pleural Mesothelioma

Mesothelioma specialists use three staging systems to characterize pleural mesothelioma, including the Butchart system, Brigham system and the TNM system. Though all three describe the cancer similarly, many doctors prefer the TNM system because it is updated frequently with the latest mesothelioma information. The TNM system notes the size and location of tumors, any lymph node involvement, and the extent of metastasis.

According to the most recent edition, researchers updated descriptions for stage 1 malignant mesothelioma, which is characterized by two categories.

Stage 1 Peritoneal Mesothelioma

With only about 500 cases each year, research for peritoneal mesothelioma is more limited. As such, doctors haven’t developed specific staging systems for this form of the disease, instead relying on general mesothelioma characteristics or the Peritoneal Cancer Index (PCI). When using PCI, doctors score the size and amount of visible tumors located in 13 distinct regions of the abdomen. The scores are added together, with the totals implying the cancer stage. Researchers have estimated a score of 1 – 10 indicates stage 1 abdominal cancer.

Stage 1 Pericardial Mesothelioma

Diagnosing pericardial mesothelioma at this stage is extremely difficult, given the cancer’s rarity and aggressive nature. Though all forms of mesothelioma can be considered aggressive, researchers have seen pericardial mesothelioma progress even more quickly because of its location and the severity of symptoms. Unfortunately, the majority of patients with this form of mesothelioma are diagnosed at advanced stages or posthumously.

Symptoms of Stage 1 Mesothelioma

Stage 1 mesothelioma tumors tend to be small and localized, so symptoms are usually absent or very mild. This is why patients are rarely diagnosed at this stage. For patients who do experience symptoms, they can be easily mistaken for common ailments, like a cold or the flu.

Stage 1 Mesothelioma Life Expectancy

Because the tumors are localized, stage 1 mesothelioma patients have more curative treatment options and a better prognosis. Average life expectancy with such an early diagnosis is 21 – 40 months, though some patients have been able to survive for 5 years or longer.

In addition to an early stage diagnosis, patients’ prognosis varies depending on the type of mesothelioma, cell type, genetics, overall health, as well as the age and gender of the patient. Many of these factors will also impact the available treatment options

Stage 1 Mesothelioma Treatment

A mesothelioma specialist will develop a mesothelioma treatment plan based on an individual’s specific case. Often, mesothelioma is treated with a combination of treatments, including surgery and chemotherapy. At early mesothelioma stages, curative surgery is still an option and often offers the best chance at extended survival.

Surgery

Mesothelioma surgery is often only a treatment option for patients diagnosed at stage 1 or stage 2, since the cancer is localized. Many of these surgeries are considered aggressive treatments because they are quite extensive and invasive. Some pleural mesothelioma patients undergo an extrapleural pneumonectomy (EPP), which entails the removal of the entire diseased lung, the pleural lining of the chest and heart, and the diaphragm.

While EPP is considered one of the most radical treatments, patients do have other less extreme options. These surgeries are often followed with chemotherapy and sometimes radiation therapy to eradicate remaining mesothelioma cells.

Chemotherapy

Chemotherapy alone doesn’t have a high success rate, with studies showing a 5-year survival rate of about 4%. When combined with surgery, however, researchers have seen better results and some patients extended survival beyond 5 years. Clinical trials continue to test new combinations of chemotherapies, as well as chemotherapy with other emerging treatments like immunotherapy.

Newer applications of chemotherapy have also seen success, with treatments like hyperthermic intraperitoneal chemotherapy (HIPEC), which is a heated chemotherapy wash, and Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC), which uses a pressurized gas application of chemotherapy. HIPEC combined with surgery has helped peritoneal mesothelioma 5-year survival rates improve to well over 50%, with some studies finding survival of 67% or higher. PIPAC, though still in its early phases, has also shown promise in a recent study where patients experienced a median survival of 26.6 months.

Radiation

Rarely an individual treatment, radiation therapy is sometimes applied following surgery and chemotherapy to kill cancer cells. Patients diagnosed at advanced stages are rarely treated with radiation, as it is a localized treatment. Radiation therapy can also cause some more serious side effects, as the treatment often damages healthy tissue.

Clinical Trials & Emerging Treatments

Immunotherapy and other emerging treatments have shown promise in treating mesothelioma, even for patients with more advanced disease. While immunotherapies like pembrolizumab (Keytruda) have been the focus of many clinical trials and have shown success in extending life expectancy, researchers are also developing new immunotherapies and combinations in early phase trials.

Personalized cancer vaccines, which are created based on a tumor’s individual genetic makeup, have become a bigger focus of cancer research. Some early clinical trials have found the vaccines could extend mesothelioma life expectancy to over 5 years for some patients. Other new forms of immunotherapy, like immune modulators, are also proving effective in reducing tumor size and improving overall survival. Researchers hope to see some forms of immunotherapy become FDA-approved for mesothelioma soon to extend survival benefits to more patients.